Synapsin I is structurally similar to ATP-utilizing enzymes.
Synapsins are abundant synaptic vesicle proteins with an essential regulatory function in the nerve terminal. We determined the crystal structure of a fragment (synC) consisting of residues 110-420 of bovine synapsin I; synC coincides with the large middle domain (C-domain), the most conserved domain of synapsins. SynC molecules are folded into compact domains and form closely associated dimers. SynC monomers are strikingly similar in structure to a family of ATP-utilizing enzymes, which includes glutathione synthetase and D-alanine:D-alanine ligase. SynC binds ATP in a Ca2+-dependent manner. The crystal structure of synC in complex with ATPgammaS and Ca2+ explains the preference of synC for Ca2+ over Mg2+. Our results suggest that synapsins may also be ATP-utilizing enzymes.
Esser
L
L
Howard Hughes Medical Institute, Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas 75235-9050, USA.
Wang
C R
CR
Hosaka
M
M
Smagula
C S
CS
Südhof
T C
TC
Deisenhofer
J
J
D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism; D002417:Cattle; D018360:Crystallography, X-Ray; D019281:Dimerization; D005981:Glutathione Synthase / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D010453:Peptide Synthases / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D013329:Structure-Activity Relationship; D016704:Synapsins / Q000737:chemistry* / Q000378:metabolism
D016704:Synapsins; D000255:Adenosine Triphosphate; D010453:Peptide Synthases; D005981:Glutathione Synthase; C019638:D-alanylalanine synthetase; D002118:Calcium